Credit to @Jirachi for helping to create this thread
Here is a collection of data and Movests for Chansey. Some data is taken from Serebii and movesets can be used in smogon and vgc, click here for more information

Competitive Sets:<Pokemon> Moveset <PlayStyle> <Tier> - <set type>: (link goes here)All general discussion about this pokemon should be in this post, competitive set can be posted in this set or in their own threads to be linked to, for more information on how to format your competitive set, click here (link will be added soon).

Togekiss and Jirachi are commonly preferred to Chansey as Serene Grace (ab)user, but TPCi gave us a VGC without both of them, so now the time is come: Chansey can finally show how powerfull her Rock Slide is.
Eggcellent (Chansey) (F) @ Eviolite
Ability: Serene Grace
Level: 50
EVs: 92 HP / 4 Atk / 156 Def / 4 SpD / 252 Spe
Jolly Nature
- Rock Slide
- Thunder Wave/Toxic
- Heal Pulse/Toxic
- Protect/Toxic
The spread increase of one point the regain of Grassy Terrain and maximize is Spe, making her faster than every other pokèmon under Tailwind, the best (or maybe the only) form of Speed control that you can use alongside this set. SpDefensively is already good, so the leftovers should be put in Def. Eviolite is the only item you should use, and Toxic is the only way to deal some damages to oppo's mons. Thunderwave can be used to increase Rock Slide's effectivity or replacing Tailwind support.
The Tailwind user in your team shouldn't be passive like Chansey, or you'll have half of your team doing quite nothing.
Does it work? Sometimes.http://replay.pokemonshowdown.com/gen7vgc2017-596957592